Electric lamp and manufacture thereof



Feb. 20, 1951 A. GREINER ELECTRIC LAMP AND momma 'IHEREOF' Filed Sept. 1, 1949 ITWVGTWEOV AlfFred Greiner, 8 M M His Ark-Horn H Patented Feb. 20, 1951 ELECTRIC LAMP AND MANUFACTURE THEREOF Alfred Greiner, Cleveland Heights, Ohio,

to General Electric Com New York assignor pany, a corporation of Application September 1, 1949, Serial No. 113,654

6 Claims. 1

My invention relates to electric incandescent lamps or similar devices and to methods of manufacture thereof. The invention is of particular utility in connection with the manufacture of electric incandescent lamps of the miniature type.

Electric incandescent lamps as manufactured at present are generally provided with a separate base member which is either cemented or mechanically afiixed to the glass envelope or bulb of the lamp. The use of such a separate base member, together with the added lamp manufacturing or basing operations required to affix the base to the lamp bulb, adds to the total manufacturing cost of the finished lamp. In the case of a miniature type lamp such added manufacturing cost usually represents a greater percentage of the total cost of the lamp than it does in the case of the larger type lamps.

It is one object of my invention, therefore, to provide an electric incandescent lamp construction which will eliminate the usual lamp base and basing operations heretofore required in the manufacture of such lamps.

Another object of my invention is to provide an electric incandescent lamp of novel and simple construction and which is relatively easy and inexpensive to manufacture.

Another object of my invention is to provide a novel method of manufacturing an electric incandescent lamp.

In accordance with the invention, the lead-in wires of the mount for an electric incandescent lamp of the butt-seal type are provided with laterally extending relatively rigid outer portions having retroverted free ends, which outer leadin portions are sealed through the butt-seal of the lamp envelope to project laterally outward from the envelope wall and form terminal contacts for the lamp, the retroverted free ends of said outer lead-in wire portions re-entering and also being sealed in the butt-seal to firmly anchor them in place in the envelope wall.

Further objects and advantages of my invention will appear from the following detailed description of a species thereof and from the accompanying drawing in which:

Fig. 1 is a perspective view on an enlargedscale of an electric incandescent lamp comprising my invention; Fig. 2 is a longitudinal sectional view thereof; Fig. 3 is a transverse section on the line 3-3 of Fig. 2; and Figs 4 and 5 are views illustrating, respectively. successive steps in the manufacture of an electric incandescent lamp according to the invention.

" Referring to the drawing, the lamp according to the invention is, in general, of the butt-seal type disclosed in U. S. Patent 1,742,153, Stiles et a1., and is fabricated in the same general way. As shown in Figs. 1-3, the lamp comprises a sealed glass envelope I consisting of a glass bulb 2 joined at its tubular neck end 3 to a glass exhaust tubulation 4 by a fused butt seal 5 (Fig. 2). The envelope I is evacuated. and filled if desired with a suitable inert gas, through the exhaust tubulation 4 which afterwards is tippedoil as indicated at 6 to hermetically seal the envelope.

Sealed within the envelope I is a lamp mount 1 similar to that employed in miniature lamps of the butt-seal type and comprising a pair of leadin wires 8-8 fused through a vitreous: bead 9, and a filament I0, preferably of tungsten wire, connected between the inner ends of the lead-in wires. Adjacent the tubulated end of the envelope, the lead-in wires 8-8 are formed with laterally extending portions II-II which extend oppositely away from each other. The said laterally extending wire portions IIII pass out through the envelope wall and are sealed through the fused butt-seal 5 of the lamp envelope I in the same manner as is customary in butt-seal lamps in general. For the purposes of the invention, the lead-in wires 8-8 are made of silverplated iron containing a small percentage of carbon, e. g., .05 per cent, and they are of a diameter large enough (e. g, around /2 millimeter. to possess the required rigidity to permit the use of their projecting outer ends as terminal contacts.

The glass envelope I is made of a suitable lowmelting point glass which matches the expansion characteristics of the lead-in wires 88 and which readily wets and seals thereto. For sealing to silver-plated iron lead-in wires such as are preferably employed. I have found a soft lead glass of approximately the following composition to be particularly suitable:

Percent S102 PbO 35 A: 2 NazO 3 K20 14 LizO '1 If desired, the lithium oxide in the above compositlon may be omitted.

In accordance with the invention the laterally extending portions II--II of the lead-in wires 88 project laterally outward of and beyond the envelope wall from the points where they pass therethrough and are retroverted or bent back upon themselves outwardly'of the envelope, as indicated at I2, to form terminal contact loops I3--I3 which protrude from opposite sides of the envelope and the planes of which are approximately transverse to the axis of the bulk neck and preferably coincident with each other. The

retroverted or free ends ll-il of the lead-in wires extend generally parallel to and are preferably spaced from the seal portions ll-ll of the wires, and they re-enter and are sealed into the butt-seal in the envelope wall to firmly anchor the said retroverted ends ll-H in place in said wall and additionally rigidify or support the contact loops l3-l8 from the envelope.

The lamp according to the invention is preferably made by first fabricating the mount 1 to final form, with its laterally extending lead-in wire portions ll-H provided with the contact loops l3-l3. With the glass bulb 2 supported in an inverted position with its open neck end 8 up as shown in Fig. 4, the finished mount 1 is inserted in the bulb in the manner shown with its laterally extending lead-in wire portions II- resting on the upper edge ii of the bulb neck. A length of glass exhaust tubing I8 is then brought down endwlse to and in alignment with the open end of the bulb neck 3, as shown in Fig. 4, and is fused thereto at 5 and drawn out to a rather small exhaust neck I! fairly close above the fused butt-seal joint 5, as shown in Fig. 5, and as d sclosed in the aforesaid Stiles et a1. Patent 1,742,153, forming an end enclosure or exhaust tubulation 4. Through the tube IS the envelope I is then exhaust and, if desired, charged with any suitable inert gas, after which the tube is is heated and softened, and fused and sealed-off at the neck l1, thus completing the end enclosure of exhaust tubulation l with the central outward projecting exhaust or seal tip 6 as shown in Fig. 1.

Although a preferred embodiment of my invention has been disclosed, it will be understood that the invention is not to be limited to the specific construction and arrangement of parts shown, but that they may be modified within the spirit and scope of my invention as defined by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric device comprising a sealed glassenvelope, an electrical energy translation device in said envelope, a pair of lead-in wires connected to said translation device and having relatively ri id outer portions extending and sealed through the wall of said envelope, said lead-in w res projecting laterally outward from and beyond the envelope wall and being retroverted outwardly of the envelope to form protruding terminal contacts for the lamp, the retroverted ends of said lead-in wires re-entering and being sealed in the envelope wall to anchor them therein.

2. An electric device comprising a sealed glass envelope, an electrical energy translation device in said envelope, a pair of lead-in wires connected to said translation device and having relatively rigid outer portions extending and sealed through the wall of said envelope at opposite sides thereof, said lead-in wires projecting laterally outward of and beyond the envelope wall from their envelope seals and being retroverted outwardly of the envelope to form protruding looped terminal contacts on opposite sides of the envelope, the retroverted ends of said lead-in wires re-entering and being sealed in the envelope wall to anchor them therein.

3. An electric device of the butt-seal type having a sealed envelope comprising a glass bulb joined to a glass tubulation by a fused butt-seal, an electrical energy translation device in said envelope, a pair of lead-in wires connected to said translation device and having relatively rigid outer portions extending through the wall of said envelope and sealed in the butt-seal therein, said lead-in wires projecting laterally outward from and beyond the envelope wall and being retroverted outwardly of the envelope to form protruding terminal contacts for the lamp, the retroverted ends of said lead-in-wires re-entering and being sealed into the said butt-seal in the envelope wall to anchor them therein.

4. An electric device of the butt-seal type having a sealed envelope comprising a glass bulb joined to a glass tubulation by a fused butt-seal, an electrical energy translation device in said envelope, a pair of lead-in'wires connected to said translation device and having relatively rigid outer portions extending through the wall of said envelope at opposite sides thereof and sealed in the butt-seal therein, said lead-in wires projecting laterally outward of the envelope from their envelope seals and being retroverted outwardly of the envelope to form protruding looped terminal contacts on opposite sides of the envelope, the retroverted ends of said lead-in wires re-entering and being sealed into the said butt-seal in theenvelope wall to anchor them therein.

5. An electric incandescent lamp of the butt seal type having a sealed envelope comprising a glass bulb provided with a neck portion joined to a glass exhaust tubulation by a fused butt-seal, a filament in said envelope, a pair of lead-in wires connected to said filament and having relatively rigid outer portions extending through the wall of said envelope at opposite sides thereof and sealed in the butt-seal therein, said outer lead-in wire portions projecting laterally outward from and beyond the envelope wall and being retroverted outwardly of the envelope to form protruding lamp terminal contact loops the planes of which are transverse to the axis of the bulb neck, the retroverted ends of said outer lead-in wire portions re-entering and being sealed into the said butt-seal in the envelope wall.

6. In the manufacture of an electric incandes-y cent lam of the butt-seal type, the steps of shaping the lead-in wires of the lamp mount with laterally extending outer portions having retroverted free ends, and butt-sealing an exhaust tube to the open end of the lamp bulb with the laterally extending portions of the mount lead-in wires projecting out between and their retroverted free ends re-entering between the exhaust tube and the bulb end whereby to seal the said laterally extending lead-in-wire portions through and anchor their free ends in the butt-s al.

ALFRED GREINER.

REFERENCES CITED The following references are of record in the flle of this patent: I

UNITED STATES PATENTS Num er Name Date 277.646 Weston May 15, 1883 1,923.144 Graf Aug. 22, 1933 2,120,087 Clemence June '7, 1938 FOREIGN PATENTS Number Country Date 472,753 Great Britain Sept. 29, 193'! 

